A doctors' surgery was today criticised after failing to diagnose a man with deep vein thrombosis which later killed him.

GPs at the practice in Grampian should have diagnosed the deadly condition after he visited there four times, as well as being admitted to hospital, according to Scottish public services ombudsman Alice Brown.

She has told the practice to apologise to his family over his treatment.

The 34-year-old had been experiencing chest pains and was coughing up blood -prompting his visits to the GP's practice in November 2006.

He was initially diagnosed with a work-related injury, according to his sister, on his first visit on November 3 when he complained of chest pains.

Five days later he returned coughing up blood and a chest infection was blamed.

The following day he was admitted to hospital when he was found doubled up in pain, and there were two subsequent visits to the GP's practice.

Only in a letter referring the man to a chest clinic on November 17 did one of the two GPs he saw refer to a pulmonary embolism, but added there were "no predisposing factors".

Despite being marked urgent, the letter was never sent.

The man complained of leg pains during the final visit on November 20, according to his sister, although this was rejected by the practice.

He collapsed and died in the early hours of the following morning.

A pathologist subsequently found that he had Klinefelter's Syndrome, a chromosomal abnormality, with sufferers having an increased incidence of pulmonary thrombo-embolism.

The ombudsman investigated after complaints from the man's sister.

A medical adviser found that the practice should have diagnosed the problem earlier.

The ombudsman's report states: "The adviser has indicated that he would expect a reasonable general practitioner to have made a differential diagnosis of pulmonary embolism earlier on and have urgently sent Mr A to hospital to have relevant tests carried out.

"The practice delayed in making a differential diagnosis of pulmonary embolism."

The ombudsman has called on the practice to apologise to the man's family for the "poor management" of his condition and consider what lessons can learned in treating young adults with chest pains.