Basically Sam Bankman-Fried (crypto billionaire subsequently done for fraud) donated 500k to a think tank. The think tank later gave 35k to Streeting. Apparently some other Labour figures declined gifts as they weren't sure where the money came from.
I don't think SBF had been found guilty at the time though.
It's not really in the same league as being in direct cahoots with a money launderer and taking 5m quid and pretending it's not a political donation.