THE sister of a North-East oil worker, who died a month after his kidnapped daughter was released by Nigerian gunmen, is convinced his death was triggered by the ordeal.

Michael Hill, 60, postponed UK medical treatment when his three-year-old daughter, Margaret, was held to ransom.

He had, however, been due to return to the North-East this week for the first time, bringing with him his daughter, who would have met her aunt for the first time.

His sister, Catherine Duffy, told The Northern Echo how Mr Hill was due any day at her home in Murton, County Durham, for a month's stay with wife Tina and Mrs Duffy.

"We were all so excited about seeing Margaret for the first time and then we got the terrible news of his death.

"I spoke to him the weekend before he died and he told me he was just waiting for Margaret's passport to come through. He was overjoyed to be bringing the daughter he absolutely idolised to meet his family."

Mrs Duffy, however, revealed the deep impact the kidnapping had had on her brother and his wife.

"We all can't help but think it was that terrible ordeal which has triggered his death,'' she said yesterday.

Mr Hill had told her that he was having treatment for kidney trouble and possible diabetes, but that he had been taken off the medication because it had not suited him.

Unable to keep his UK medical appointments during the harrowing days of the kidnapping, he had however, made new appointments to see doctors on his return.

Mrs Duffy, who confirmed that her brother's funeral would take place in Nigeria, had spoken to Mrs Hill on Tuesday night and said: "She is very low and she confirmed to us that his death certificate stated he had died of a heart attack.''

Mrs Duffy said she had been very close to her brother who, after her own husband's death in 2000, had tried to persuade her to go and live in Nigeria.

"I preferred to stay at home and I even asked if he would return, but he told me he loved Nigeria and he said being with Tina and Margaret had been the happiest years of his life.''

She described how Mr Hill also ran a bar with his wife in Port Harcourt, Nigeria, where they held charity evenings, giving all the proceeds to the poor.

"He was highly thought of in the community and was even made an honorary chief of one of the tribes out there,'' she said.

He was also highly respected in the former pit village where he was born and brought up.

She said: "Since the news of his death, I have had several phone calls from old friends and after his funeral in Nigeria I am hoping to hold a memorial service in Murton.''

Mr Hill's son, David, who lives in Sunderland and for a time worked with his father in Nigeria, said last night: "We can't believe it. He had been looking forward to coming over.

"After everything that's happened, they just wanted a bit of a break.''