The investigation into payments totalling €7.3 million (£6.4 million or $7.8 million) Barcelona made to a former referees chief has widened, with the Catalan club now facing further charges.

Barca, ex-club officials and the former vice-president of Spanish football’s refereeing committee, Jose Maria Enriquez Negreira, were indicted for “corruption”, “breach of trust” and “false business records” in March, in a case brought by public prosecutors.

This Wednesday, a document published by the Barcelona court dealing with the case said a further charge of “bribery” would now be attributed to all those investigated. This could, in theory, lead to stricter punishments and would see the case tried by a jury if it made it to court.

Meanwhile, early on Thursday morning, Guardia Civil police officers visited Spanish FA (RFEF) headquarters looking for documents relating to Negreira’s time as a senior official. Earlier in September, the investigating judge, Joaquin Aguirre Lopez, said no evidence had yet been found of Negreira paying referees to influence match results.

Negreira has denied ever favouring Barcelona in terms of refereeing decisions. Barcelona have also denied any wrongdoing and earlier this year said they hired Negreira as an “external consultant” who provided reports “related to professional refereeing”.

Prosecutors have also charged two of Barca’s former presidents, Sandro Rosell and Josep Maria Bartomeu, with false administration and falsifying a commercial document.

Two other former officials from Bartomeu’s time as club president were charged as well: Oscar Grau and Albert Soler. All four have acknowledged the payments to Negreira but denied wrongdoing.

• The Athletic report