* Former Danske Bank Estonian branch boss found dead
* Aivar Rehe had been missing since Monday
* Rehe was head of Danske Estonian business 2007-2015
* Prosecutor says Rehe was witness in investigation (Adds background, details, Deutsche Bank raid)
By Tarmo Virki
TALLINN, Sept 25 (Reuters) - A former head of Danske Bank's Estonian branch, which is at the centre of inquiries into the world's largest money laundering scandal, was found dead on Wednesday.
Police in Estonia discovered the body of Aivar Rehe, who ran the Danish bank's Estonian business between 2007 and 2015 and had been among those questioned as a witness in a probe by Estonian prosecutors, following a search which began on Monday.
Danske Bank, Denmark's largest lender, is under investigation in several countries, including the United States, Denmark, Britain and Estonia, over suspicious payments totalling 200 billion euros ($220 billion) which were moved through its tiny Estonian branch during the period Rehe was in charge.
Rehe's death is likely to complicate investigations into Danske Bank's Estonian operation, including by U.S. authorities.
The former banker's importance in investigating the case was highlighted by the fact that he had been quizzed, as a witness, by Estonian prosecutors.
Danske Bank's is the largest in a series of European money laundering scandals, stretching from Latvia to Sweden.
And in a sign of the wider ramifications of the case, Frankfurt prosecutors said they had raided Deutsche Bank's headquarters in the German financial capital in relation to Danske Bank. Deutsche Bank said it was cooperating.
Estonian police said that Rehe had not been seen since he left his home in Tallinn, Estonia's capital, on Monday.
Estonian prosecutors confirmed that Rehe had been questioned as a witness, not a suspect, in a case opened in December last year against 10 former Danske Bank employees. This involves the alleged laundering of around 300 million euros.
The police said Rehe's death would not be investigated.
"There are no signs of violence on the corpse, and there is no indication of an accident ... There will be no investigation opened," police said after finding Rehe's body near his home.
Estonian police had issued a missing persons appeal on Monday, saying Rehe had left his home that morning and his family had no information about his whereabouts.
Dozens of people had joined a search for the 56-year-old in forests around his home in a Tallinn suburb, a well-off neighbourhood of small houses which is surrounded by large areas of parkland.
"He was questioned as a witness in the case," a spokeswoman for the Estonian prosecutor's office said of Rehe, adding that the investigation was continuing.
The spokeswoman declined to give any further details, while the Danish prosecutor declined to say whether Rehe was or had been the subject of its investigation.
Danske Bank extended its condolences to Rehe's family.
"We are sad to receive the news that the former chief of our Estonian brand, Aivar Rehe, is dead. Or thoughts go out to the family," it said in a statement.
Rehe rarely spoke publicly about the case, which began to come to light in 2017, but he had said that he felt responsible even though he thought anti-money laundering measures had been sufficient at the time.
"I do. Naturally. I spent 10 years running that bank, and they were all my people," he said in an interview with Estonian media outlet Postimees in March. ($1 = 0.9093 euros)
Reporting by Tarmo Virki; additional reporting by Stine Jacobsen in Copenhagen; Editing by Jon Boyle and Alexander Smith