Hello Wiggy, have a look at this web for starters. I only use horse/stable manure for this very reason. Have you already incorporated the manure into the soil ?
Let us know what you do as we all need to be aware of such issues.

www.allotment.org.uk/garden-diary/273/aminopyralid-contaminated-manure · Cached page

Hi Bizzyb

Yes we put it under our potatoes when we planted them this year noticed the curled leaves on some of them and realised it must have been the manure that we got from a plot on our site that had been given up we have had potatoes from the plants but not many .we have been told that if you turn the affected ground over 3-4 times it should be ok to grow in next year i hope this is the case i will look at the web site you have suggested thanks

Wiggy