A mysterious metal plate caught in the fishing net of a boat off Mangrol coast is foxing security agencies.

According to sources in custom department and security agencies, the plate is 3.5-feet-long with the diameter of 12 centimetre. It was found in the net of Devu Machh, who had gone for fishing in his boat Varun Devta' on October 26.

"We informed the custom department and handed over the plate to them on October 29," said Machh. At present, the plate is being kept at the custom department office. "We're yet to identify the metal, which looks like scrap. There are some numbers written on it in black letters which are indecipherable," said a custom official.