Spain's Prime Minister Mariano Rajoy is facing renewed calls to resign after a newspaper published text messages allegedly linking him to the man at the centre of a secret payments scandal, BBC News said.

The El Mundo report said Rajoy sent words of support to Luis Barcenas, former treasurer of the governing Popular Party (PP).

Barcenas is in custody facing trial for corruption and tax fraud. He denies the allegations. Rajoy, too, denies any wrongdoing.

It is the latest episode in a scandal that has enraged a country in the depths of recession and record unemployment.

Previous reports in El Mundo have alleged that Rajoy and other top politicians received illicit payments. The paper said it had original ledger entries written by the former PP treasurer.

It is claimed that Barcenas ran a PP slush fund that took donations from construction magnates and distributed them to party leaders in cash.

Another Spanish paper, El Pais, published similar documents earlier this year.