Former Spanish Football federation (RFEF) president Luis Rubiales was detained for a few hours on Wednesday in connection with a corruption probe relating to contracts during his term.
Rubiales was met by police at Madrid airport upon his return from the Dominican Republic and questioned before being released again.
An official statement was yet to be released but a Guardia Civil spokesman told dpa that the report from broadcasters RTVE was correct.
Rubiales is expected to be questioned by an investigating judge within the next days.
Under Spanish law a suspect can be detained for up to 72 hours without an arrest warrant.
Rubiales was already in the Dominican Republic when the Guardia Civil raided RFEF offices and other properties, including Rubiales home on Granada in mid-March in connection with a corruption and money laundering investigation into contracts made during his five years as RFEF president.
They are said to include the deal to hold the Spanish Super Cup as a four-team tournament in Saudi Arabia, completed by Rubiales together with businessman and former Barcelona player Gerard Pique.
Rubiales stepped down in September over the women’s World Cup kissing affair, having kissed Spanish player Jenni Hermoso on the lips without her consent.
He is under criminal investigation over that incident as well in Spain, and was banned for three years from football activities by the world governing body FIFA.
Rubiales has protested his innocence in both affairs