Lehman Brothers has sued Barclays Capital alleging the UK-listed bank took control of excess assets in collusion with Lehman executives when it bought its US brokerage business a year ago, court documents show, according to Reuters.

Lehman filed for bankruptcy on 15 September last year, in the largest US bankruptcy in history. Its flagship US brokerage business was sold to Barclays less than a week later.

However, the transaction has proven controversial, with Lehman claiming in September this year that Barclays Capital received an $8.2 billion “windfall profit” due to the heavily discounted sale of its business.

Barclays Capital declined to comment on the matter when contacted by Family Wealth Report.

Other takeovers agreed amid the turmoil of last autumn’s financial markets have proven controversial, sparking legal action. For example, Bank of America’s takeover of Merrill Lynch has led to accusations that BoA did not fully inform shareholders of the extent of Merrill’s losses. In the UK, Lloyds TSB’s purchase of debt-laden rival bank HBOS has also led to claims that Lloyds had damaged itself by buying a heavily indebted firm.

"The windfall to Barclays was not disclosed to the Court, the Lehman Boards or Lehman's lawyers so as to allow the transfer to Barclays of billions of dollars in excess assets, without consideration, in a manner designed to avoid judicial, corporate and creditor oversight," Lehman said in a court filing, the news agency reported.