Jozsef Szajer is a senior member of Hungary's ruling Fidesz party

A Hungarian Euro MP close to conservative PM Viktor Orban who quit his job has admitted his resignation came after he attended a house party in Brussels, violating lockdown rules.

Police broke into what Belgian media describe as a gay sex party on Friday.

Jozsef Szajer, a top official in Mr Orban’s Fidesz party, apologised for “a personal failing”. Reports say he tried to flee down a drainpipe.

Fidesz is hostile to LGBT rights and backs traditional family values.

The party in an apartment in central Brussels was attended by 25 people, mostly male, and was raided by police on suspicion of breaking coronavirus restrictions.

The Belgian news agency Belga says some of the participants were naked when the police burst in. The police cautioned them for having broken the lockdown rules.

The BBC’s Nick Thorpe in Budapest says Mr Szajer’s sudden resignation as an MEP on Sunday surprised his political friends and foes alike. He had blamed “increasing mental strain” for the decision.

On Friday he pleaded parliamentary immunity, but he is now under investigation.

The European Parliament said the immunity rule only extended to an MEP’s official duties, not to his or her private life.

In a statement on Tuesday, Mr Szajer admitted he had attended the party on Friday, but did not describe it.

“I didn’t use drugs, I told the police on the spot I was willing to undergo an official test, but they didn’t do one. The police said an ecstasy pill was found. It was not mine, I don’t know who planted it or how. I made a statement to the police about this.

“I am sorry that I broke the rules of assembly, this was irresponsible on my part, and I will take the sanctions that come with it,” he said.

Belgium’s De Standaard daily says the usual fine for breaking the Covid rules on assembly is €250 (£224).