I would discuss with ICB if you have doubts
Does Companies House filing reveal any wrong doings?
If loans are involved are any debentures in place as charges?
Might be worth checking for other directorships for the directors
There may also be other companies that you do not know about
Might be all above board but you can check quite a bit
I did a check on one of my suppliers a couple of years ago
and they found 13 bars of gold bullion in the safe!