The father of Ibragim Todashev, who was shot by an FBI agent a week ago while being quizzed over his links to the Boston bombers, revealed the extent of his son's injuries in gruesome photographs of his dead body today.

Outspoken Abdul-Baki Todashev called for an investigation and possible legal action against the agent involved at a press conference in Moscow where he showed the images of his son's body lying in a morgue with up to seven gunshot wounds, including one to the back of the head.

His angry calls for justice came as a report claimed the 27-year-old native Chechen was unarmed in the clash with a federal agent in Florida on May 22. Previous reports claimed the US citizen went for the agent with a knife while being interrogated in his home. However, a report by the Washington Post yesterday cited law enforcement officials saying he had no weapon.

Additional images (graphic content)

He allegedly did become violent when police quizzed him over links to Tamerlan Tsarnaev and an unsolved 2011 triple homicide but he did not have a knife as previously claimed.

'Today I want justice. I want an investigation, so that these people (the FBI) are sued under US laws,' he said.

'These are not FBI agents. These are bandits and they must appear in court.'

He said he received the 16 images of his son's body from a friend in the US.

Todashev is pictured lying in a Florida morgue. His father claims they show brutal injuries from up to seven bullets including one to the back of the head.

'This is not a shot that you fire when you come under attack. This is a shot you fire to execute someone,' he said.

'Couldn't they just handcuff him? At the very least, they could have wounded him in the foot or shoulder. And here he was - killed execution style.'

He added that his son must have had information they didn't want him to reveal.

'They silenced him', he added.

He now plans to journey to the US to pick up his son's body and said he had been to the US embassy in Moscow to apply for a visa to do so.

Authorities were pressuring the younger Todashev to make a full confession to the murders of three men found in an apartment in Waltham, Mass. on the tenth anniversary of the Sept. 11, 2001.

It is known Tamerlan Tsarnaev was close friends with one of the victims and the FBI have been looking into whether he was involved.

Law enforcement sources told NBC that Todashev and Tsarnaev carried out the 2011 killings when a drug deal that turned violent. The suspects didn't want the three victims to be able to identify them, so they slit their throats, according to the network.

It is that evidence which apparently led them to Todashev and his Orlando apartment not far from Universal Studios on May 22.

He had questioned for some hours before he allegedly flipped and the shooting came as one agent stepped out of the room, leaving Todashev alone with one officer, the Post said.

Tsarnaev's mother, Zubeidat Tsarnaeva, confirmed to the New York Times on Wednesday that her older son knew Todashev.

In a telephone interview from Dagestan, Tsarnaeva said Todashev moved from Boston to Florida about two years ago. She said she is devastated to learn that he has been killed.

'Now another boy has left this life,' she told the newspaper. 'Why are they killing these children without any trial or investigation?'

The FBI has been investigating Todashev for the last month, questioning him several times regarding his ties to Tamerlan Tsarnaev, who was killed by police in a shootout following the deadly April 15 marathon bombings.

Authorities said they have no reason to believe that Todashev had any involvement in the marathon bombings.

Todashev was arrested in an unrelated incident on May 4 for aggravated battery after he left a man unconscious in the parking lot of a shopping mall.

According to the arrest affidavit, Todashev had gotten into an altercation with a man and his son over parking space.

Todashev told police that the man 'got into his face' so he pushed him and then the man's son 'got involved' and Todashev began fighting him.

A mall security officer arrived on scene to find the son unconscious and lying in a pool of blood on the ground just as Todashev was pulling away in a white Mercedes.

The officer chased down the Mercedes, ordered Todashev out at gunpoint and arrested him.

The son was later treated at a hospital with a split upper lip, several teeth knocked out and head injuries.

Friends and family members of the 2011 murder victims reacted to news of that Tsarnaev and Todashev were involved on social media.

On a Facebook page dedicated to victim Raphael Teken, someone wrote, 'Whether we ever know exactly what happened, there is one thing we surely know and that is that Rafi deserved a much better fate.'

Facebook user Tony Porter wrote, 'I'm disappointed that we will never really get to experience true justice for our friend or know the reasons for what happened despite the fact that both alleged suspects are now deceased.

'I don't know how you are supposed to feel when your friend's killer gets killed, but I don't feel "relieved" like I thought I would.'