The Dutch security service AIVD has foiled ‘three or four’ serious potential terrorist attacks in the Netherlands over the past six years, according to the organisation’s chief.

Rob Bertholee made the comments during recordings for the television chat show College Tour, in which prominent individuals are questioned by students.

Bertholee was asked by presenter Twan Huys about the attack planned by Rotterdamer Jaouad A, who was arrested in December 2016 after a tip-off.

A search of his home uncovered an automatic weapon with specially adapted anti-tank bullets, along with 9kg of illegal fireworks in his son’s bedroom.

‘If we look at something like that, then I would dare to say that we have prevented an attack,’ Bertholee said, adding immediately that ‘it is always complicated by the fact we are looking for something that has yet to happen.’

The AIVD chief went on to say that he had come across concrete terror plans two or three other times during his time in office, which started in 2011. Pressed by Huys, Bertholee said he could say with ‘absolute certainty’ that there had been three or four in total.

Bertholee did not give further details about the attacks which had been foiled, saying some are still under investigation.

The programme will be broadcast on January 21.