The business secretary, Vince Cable, said on Friday that the licenses concerned the sale of arms components from UK companies to Egypt's military and police forces.

A Foreign Office official told the British daily Guardian that the revocation was linked to reports of military and police malpractice during recent protests.

A Guardian investigation published on Thursday reported that the deaths of 51 pro-Morsi supporters on Monday 8 July was the result of a co-ordinated assault by both police and army officials on largely unarmed protesters.

The official said the UK government felt there was now an "increased likelihood" that the weapons parts could be used in the excessive repression of protesters in the near future.

"We judge that there is now a clear risk that the equipment covered by these licenses might contribute to the excessive use of force during crowd control," said the official, speaking on condition of anonymity.

It is unclear which British companies – and how many of them – have been banned from making the sales. But the official confirmed that the bans concerned the supply of armored personnel carrier components to Egypt's interior ministry, which controls the police force.

They also revoked the delivery to Egypt's military of radios, vehicle aerials, machine-gun components, tracked armored fighting infantry vehicle components, and tank communication equipment.

Tension has intensified since the Egyptian army overthrew Morsi, suspended the constitution, dissolved the parliament on July 3 and declared the chief justice of Egypt’s Supreme Constitutional Court, Adly Mansour, as interim president the following day.

Dozens of people have since been killed in the wave of violent clashes between Morsi supporters, his opponents and security forces.

SHI/SHI