(Bloomberg) -- Credit Suisse Group AG is cutting ties with SoftBank Group Corp., distancing itself from a key backer to Lex Greensill’s collapsed supply-chain finance empire after conflict of interest allegations.

The Swiss lender will no longer do any new business with the Japanese firm, people with knowledge of situation said, asking not to be identified because the matter is private. The decision may ripple across Credit Suisse’s investment bank: SoftBank has been a prolific deal-maker and last year Credit Suisse and other banks held about $8 billion of SoftBank shares in collateral, pledged by founder Masayoshi Son.

It is unclear how long the ban lasts for, or whether it impacts any ongoing deals.

Credit Suisse is reviewing its risk and client relationships after being hit by the twin collapses of Greensill and Archegos Capital Management. New Chairman Antonio-Horta Osorio has pledged a wide-ranging review after the bank was forced to suspend billions of dollars of funds it managed with Greensill and took a $5.5 billion hit on Archegos, raising questions about the oversight of key clients.

A Tokyo-based spokesperson at SoftBank Group wasn’t immediately available to comment, while Credit Suisse declined to comment.

Credit Suisse conducted an internal review into the Greensill funds after allegations of possible conflicts of interest involving SoftBank last year. A number of SoftBank portfolio companies received loans via supply-chain funds at Credit Suisse, while SoftBank was also an investor in the Credit Suisse funds. In the aftermath, SoftBank pulled $700 million out of the funds and the bank also changed its investment guidelines for Credit Suisse’s to reduce the maximum exposure to a single borrower.

Credit Suisse Overhauls Rules for Funds Accused of Conflicts

The overlapping financial relationships had raised questions whether SoftBank was using the Credit Suisse funds to prop up investments in the Vision Fund, including Greensill Capital, in which it had a substantial stake.

SoftBank wrote down its $1.5 billion holding of Greensill to close to zero after Credit Suisse was forced to wind down its four Greensill-linked funds in March, people familiar with the matter earlier said. SoftBank is now seeking $1.15 billion in claims as part of Greensill’s insolvency proceedings.

Credit Suisse marketed its popular supply-chain finance funds as among the safest investments it offered, because the loans they held were backed by invoices usually paid in weeks and the funds were insured. But as the funds grew into a $10 billion strategy, they strayed from that pitch and much of the money was lent through Greensill against expected future invoices, for sales that were merely predicted. The firm’s collapse forced Credit Suisse to liquidate the funds, and investors finally payment is still uncertain.

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