With journalists increasingly assassination targets, Peter Gillman, a former staff member on the Sunday Times‘ Insight team, looks at the murder of his colleague in Egypt in 1977.

“Take care”, Harry Evans told me. “Mossad is the best secret service in the world.”

It felt like an apt warning. Earlier that week, the body of David Holden, the Sunday Times‘ chief foreign correspondent, had been found by the roadside close to the campus of the Al-Azhar University campus in Cairo. He had been shot and his body had lain in the city mortuary for three days before being identified.

Now, on the morning of Sunday, 11 December, 1977, Harry was dispatching his reporters, me among them, to the Middle East in a bid to find out who had killed him, and why. It marked the start of a long and bewildering journey that uncovered only some of the answers, but which also illustrates the investigative techniques of the Sunday Times at that time.

The truth of journalism lies in detail, so pursue it assiduously.

Mossad was one immediate suspect. Three months before, the Sunday Times had published a devastating four-page expose of the interrogation methods used by Israeli’s security services against dissident and suspect Palestinians, which it categorised as systematic torture.

A phenomenal row ensued: the then Prime Minister, Menachem Begin, called it the most damaging article ever printed about Israel. The Israeli press had named Holden as an author of the article – and Israel had no compunction about taking revenge against its enemies. (In fact, Holden was not one of the authors, whereas I was).

During the week in Cairo, we followed our well-tried technique of assembling every possible detail about Holden’s final movements, in the hope that answers would emerge.

He had spent a week touring the Middle East covering the rapprochement between Egypt and Israel ahead of the Camp David agreement. His movements were largely those of an experienced foreign correspondent working his contacts, yet, there were gaps and inconsistencies we could not resolve.

Then, on 7 December, his killers had met him at Cairo Airport and – using re-sprayed stolen cars – had driven him around for several hours before dispatching him with a single shot from behind to the heart. The Sunday Times published a full-page report stating that Holden was the victim of a professional hit – but the motives eluded us.

We regrouped after Christmas. I was assigned to cover Holden’s tracks in the Middle East again. One of the dicta of the great investigative journalist Phil Knightley was: talk to everyone, no matter how tangential they might appear. We met embassy officials, security police, journalists, travel agents, taxi drivers. Least helpful were US officials who clearly wanted to know what we knew without giving anything away themselves. We visited the Palestine Liberation Organisation in its Beirut headquarters, where it denied killing Holden on the grounds that it had a policy of not killing journalists, least of all from the Sunday Times.

One clear possibility was that Holden had been a “spook”, involved in one or more intelligence agencies. If so, Harry vowed that the Sunday Times should reveal this ahead of anyone else.

The theory gained credence when we discovered that someone had been stealing telexes from the Sunday Times‘ wire room (this being the epoch before the internet revolutionised global communications). The thefts occurred during both of Holden’s last trips to the Middle East and our own, and the telexes in question contained full details of our travel plans. With the assistance of Scotland Yard, surveillance cameras were installed in the wire room. The thefts abruptly stopped, suggesting that someone had been tipped-off. Paranoia reigned, but we never found out who the insider might be.

We now cast our net wider still, tracking back through Holden’s life, from his childhood in north-east England, his period studying in the US and his entry into journalism. There were patterns matching those of others who had been recruited by intelligence agencies: a spell in eastern Europe, a visit to Mexico City, a bizarre relationship with a leftist academic and fantasist, a troublingly smooth passage on to the staff of The Times. But, we still had nothing firm enough to publish.

Talk to everyone, no matter how tangential they might appear.

The Holden team was finally assigned to other duties, but some of us did not give up.

Even after Harry left Times Newspapers in 1982, he worked his top-level US contacts, without a sniff. I too left the Sunday Times staff following the Murdoch takeover and the arrival of Andrew Neil. But, I remained in touch with an American diplomatic contact whom I showed a long internal memorandum I had written summarising all we knew, and surmised, about the killing.

We had already concluded that only the Egyptian secret service could have conducted such an elaborate operation in Cairo, which lay beyond the capabilities of outside agencies – even Mossad. Now, piecing together all our evidence, we came to another conclusion: the Egyptians had carried out a contract killing on behalf of another intelligence organisation, for which, by far, the most likely suspect was the CIA. As for why, we guessed that Holden had become involved with competing intelligence agencies, and had been killed for some presumed act of betrayal.

For a long time, lacking final proof, we kept our thoughts to ourselves. In 2009, in his memoirs My Paper Chase, Harry finally laid them all out, including the sinister thefts of the telexes from the Sunday Time‘ office. Our suspicions were now on the record but, even then, Harry was not content – and nor was I. Each time I have met him in recent years, he has told me he remains haunted by our inability to clinch the Holden inquiry and wished there was a way to do so. I share his feelings.

Even though this story is one of partial failure, there are ample lessons for investigative journalism, then and now. First, cover the waterfront: as Knightley put it, talk to everyone. Second, the truth of journalism lies in detail, so pursue it assiduously. Third, get out of the office and go and see for yourself, for you never know what you might find out. Fourth, pursue the truth no matter where it might lie.

These basics still apply in the current era of investigative journalism, as demonstrated by the work of Nick Davies, Carole Cadwalladr, Amelia Gentleman and others.

At the same time, new technologies have brought immense advantages: networking and collaboration are far easier, the internet has liberated many aspects of research and data-drilling slashes the time spent poring over printed documents. Most importantly, the new investigative bodies – the bureaus and the independent agencies – have both the commitment and the resources of the Harry Evans Sunday Times, as well as the vital attributes of being ready to challenge elites and tell truth to power.

Peter Gillman worked in the Sunday Times Insight team in 1975-1980.