Former Barcelona president Sandro Rosell has been arrested as part of a money-laundering investigation.
A number of other people were also held as police raided nine offices and homes in north-eastern Catalonia.
The arrests are part of an investigation into rights sales relating to Brazil, police sources say.
Rosell was Barca president from 2010 to 2014, when he resigned following a Spanish court’s decision to investigate the 2013 signing of Brazilian Neymar.
In June 2016, Barcelona paid a fine of 5.5m euros (£4.7m) over the 25-year-old’s move from Santos. The club was accused of tax fraud, which it denied.
Rosell’s wife was among those also arrested on Tuesday.
Spanish newspaper El Confidencial reports the arrests are part of a joint operation between the Spanish police and the FBI, related to the United States-led investigation into corruption at Fifa.
The investigation stems from the FBI’s investigation into corruption at world football governing body Fifa, which triggered a series of arrests of the organisation’s top officials in 2015, leaving open the possibility that Rossell could be extradited to the US to face charges.
Seven people were arrested in the raid, which was carried out on behalf of the United States Department of Justice.
More arrests and indictments on corruption charges followed in subsequent days and scores of Fifa officials and associates have since been arrested in connection with the investigation.
In March, Fifa passed on evidence from its internal inquiry to Swiss and US authorities.
Former Barcelona president Sandro Rosell was arrested on Tuesday in connection with a money laundering investigation.
Per El Mundo (h/t Marca), Spain’s National Court ordered the probe, and a joint task force, comprised of the civil guard and police, arrested him after the investigation indicated he “collected irregular commissions, obtained through the sale of the image rights of the Brazilian football team.”
The money collected was then allegedly laundered through “fictitious companies established in tax havens.” Rosell worked with the Brazilian Football Confederation prior to becoming Barca president in 2010.
The 53-year-old used his company, Ailanto Marketing, to organise friendlies for the Brazilian national side and allegedly charged “irregular” commissions for doing so.
Rosell is set to stand trial in relation to Neymar’s transfer from Santos to Barcelona in 2013.
Ricardo Teixeira, former president of the CBF between 1989 and 2012, along with other former Brazilian directors of football, have also been implicated in the investigation.
In 2012, Teixeira was, along with former FIFA president Joao Havelange, found to have accepted £28 million in payments from marketing company ISL, who previously broadcast the World Cup on TV.
Per El Mundo (h/t Marca) prosecutors want to hand Rosell a five-year jail sentence on charges of corruption in business and fraud.