A Spanish priest has admitted he leaked classified Vatican documents to journalists.

Monsignor Angel Lucio Vallejo Balda said he had felt intimidated by a woman he was romantically engaged with.

"Yes, I sent documents to journalists, I handed over a list of five pages with 87 passwords," he told a Holy See court in response to questions from the prosecution.

He said he did it "spontaneously" and was "not fully lucid". He suggested his former colleague Francesca Chaouqui, an Italian PR consultant, had coerced him into leaking the documents by threatening to reveal their relationship.

"I was convinced I was in a situation without exit," he said and claimed his actions were a result of sexual tension and blackmail.

However Chaouqui denied the pair had a sexual relationship.

The two were colleagues on a now-defunct commission appointed by Pope Francis to reform the Vatican's financial holdings.

They are now at the centre of a controversial trial, known as Vatileaks II, which resumed on Monday. The case surrounds two books which came out last year and depict the Holy See riddled with corruption and scandal. The books are based on leaked information and could see five people, including two journalists, Gianluigi Nuzzi and Emiliano Fittipaldi, imprisoned under the Vatican's anti-leaks legislation.

The laws were hastily introduced after the first Vatileaks scandal in 2013 centred on secrets revealed by the former butler of the now-retired Pope Benedict XVI.

Balda spent two months in a police cell last year before being transferred to house arrest before Christmas. However he was sent back to Vatican jail after it emerged he used a mobile phone to communicate with others while under house arrest.