An investigation into the manufacture of surgical instruments has found that just one NHS Trust has their equipment checked against British standards by a technologist.
Some 12 out of 19 sample instruments from the Pakistani city of Sialkot - one of the world's leading manufacturers of surgical equipment - failed quality tests at Barts and London NHS Trust.
Lead technologist Tom Brophy found faulty screw heads, sharp protruding guide pins and errors with soldering work.
While examining one of the sharp guide pins for the BBC Panorama investigation, he said: "We are trying to protect the surgeon and the patient here, and that is pointed. You put your hand on that... that's just like a lance."
He told the programme that he rejects almost 20% of instruments sent to him from all suppliers, but Panorama found that the same companies who supply Barts are free to supply more than 180 other health trusts and boards in the UK.
Three NHS surgeons told the report that they were unhappy at the quality of the equipment they have to use.
One said: "You look at your glove, which has been torn by a rough edge of an instrument, and you think, have I just cut that patient's bowel with this?
"If we filled in a form every time an instrument failed, we would spend the morning operating and the afternoon doing paperwork."
Surgical instruments have to meet standards set by the Medicines and Healthcare products Regulatory Agency.
A spokesman told the BBC that "it has no evidence that non-compliant instruments are being supplied to the NHS" and if issues did arise then it has "a range of powers and sanctions available to deal with the problem."