A now deceased "friend" took a cheque made out to her partner, forged his signature, then talked the bank into cashing it and used it to pay off some of her debts. I believe the bank is liable. This took place in 2002 but did not come to our attention until after her death in 2008.

Why would the bank be "liable"? Was an employee there part of the fraud, did they know she faked the check ?

Next was the check to the partner money to the business, so the funds would have some right to belong to the business.

Next are you concerned about criminal ? Since she is dead, that is not an issue.

The partner may have a civil claim against the estate, but if she died in 2008, I would assume the estate would be over my now?

Well, our thought is, the bank should have never cashed a certified cheque made out to John Doe for $60 000, unless John Doe was doing the cashing. Allowing someone else to cash a cheque of this amount, without knowing for sure that it was not a forged signature, seems to suggest liablity?
The money had nothing to do with a business... in fact, she scammed me and gave me a Promissory note, again with a forged signature from her partner, to talk me into lending him the money. Turns out she had scammed a lot of people... including her partner... but this did not come out till the day of her death. She died with thousands of dollars owing to many people so... nothing to get from her. Just seems the bank could have avoided this problem by not allowing a cheque... especially of this magnitude... to be cashed by someone else. We are in BC Canada.

If this was her business partner, and they often handled large sums at the bank, whilie perhaps they should not, I doubt there are any laws ( just bank policies) and of course did the partner not notice right away that 60,000 was missing ?

But there will have to be proof that the bank knew it was a fake or fraud signing, in that case it is again a criminal issue also.

But in most cases if the estate did not have any funds to repay people who were frauded, they are just out the money.

I guess I should have been clearer... it was not her "business" partner... but her significant other... who she eventually married (fortunately he got a prenup before marrying so is not liable for her debts).