(Adds detail of document, comment from Cunha, Comment from BTG Pactual in paragraph 5))
SAO PAULO, Nov 29 (Reuters) - Brazil's federal police found documents allegedly linking investment bank Grupo BTG Pactual SA to the payment of bribes to ruling coalition lawmakers, the online edition of O Globo newspaper said on Sunday.
According to Globo, which did not say how it obtained the information, the documents were seized in the home of an aide to Senator Delcídio do Amaral, who was arrested on Wednesday for allegedly trying to obstruct a corruption investigation.
The documents, Globo said, contained notes alleging that BTG Pactual paid 45 million reais ($11.7 million) to Eduardo Cunha, speaker of Brazil's lower house of Congress, in exchange for the passage of legislation favoring the bank.
The legislation, part of an executive decree, allowed the use of tax credits obtained from the acquisition of failed banks, Globo said. Cunha then allegedly shared out some of the money with other members of his PMDB party, the newspaper said.
The bill was approved in 2013, Globo said.
In a statement, BTG Pactual denied the payments and pledged to cooperate with authorities on the matter. According to the statement, changes approved the use of those credits starting from Jan. 1, 2014, later than BTG Pactual's acquisition of the failed bank's assets.
Prosecutors have already used the document outlining the alleged bribes to persuade the country's Supreme Court earlier on Sunday to extend the temporary detention of André Esteves, chairman and the largest shareholder in BTG Pactual, for an indefinite period as investigations continue, the newspaper added.
Prosecutors are now preparing to file charges against him for his involvement in "Operation Car Wash," Brazil's biggest corruption scandal ever, Globo added.
Esteves's lawyerl, Antonio Carlos de Almeida Castro, did not take calls seeking comment.
Cunha, in a statement on his official Twitter feed said the affair "was a true absurdity," adding that "for notes to appear by a person he doesn't know citing things that don't exist looks like a setup." (Reporting by Guillermo Parra-Bernal; Editing by Chris Reese)