A 41 year old man is believed to have been arrested in connection with an investigation into Primrose Associates.
City of London police have not confirmed whether the man in question is Peter Carron, managing director of Primrose.
The man has been released on bail without charge.
The south-east London man was arrested on suspicion of fraud and abusing a position of trust.
Earlier in the year Primrose Associates was placed into liquidation, leaving behind debts of £5m.
KCBS was appointed liquidator for the mortgage brokerage after a meeting of creditors.
It is believed the money which was invested in Primrose was subsequently used to develop technology systems at Evaluate.
Mortgage Strategy could not reach Carron for comment.