Detectives probing the murder of Nairn banker Alistair Wilson have taken 73 new witness statements in the last few months.
Police revealed the fresh activity in the investigation as the 12th anniversary of the shooting that shocked Scotland looms.
The Press and Journal can also reveal that officers reviewing the evidence claimed more that £5,400 for overtime, hotels and other expenses in the last year.
The figures, released under freedom of information legislation, were welcomed by politicians last night as evidence that the long-running murder inquiry remains live and active.
Mr Wilson was shot three times on the doorstep of the family’s home in Nairn’s Crescent Road on Sunday, November 28, 2004.
Doctors battled to save the life of the 30-year-old banker, but he later died at Raigmore Hospital.
A huge hunt for the killer was launched, and the murder weapon, a small Czech-made automatic pistol, was found in a drain several streets away.
But no one has ever been arrested and no motive for the murder has been established.
The case is currently subject to a homicide governance review, with detectives looking again at all lines of inquiry to ensure they have been “thoroughly exhausted”.
Last year, the Press and Journal revealed detectives had interviewed a total of 2,700 people in connection with the case since the original inquiry began.
Asked for updated figures, the force yesterday disclosed that a further 73 statements had been taken by officers since December last year.
It clarified that “there may be instances where one individual has provided more than one statement”.
Police also said detectives investigating the murder had claimed £5,424.25 in expenses in the period, including spending £2,273.70 on overtime, £2,419.65 on hotel accommodation and £317.32 on travel.
The force added that “this information does not capture all the associated costs of the investigation”.
A police spokesman said: “Under new procedures introduced by Police Scotland, the murder of Alistair Wilson is now the subject of a homicide governance review, which is looking at previous investigation strands to ascertain if all possible lines of inquiry have been thoroughly exhausted.
“Over the course of the past 12 years, detectives have worked tirelessly using a wide range of methodologies, seeking expert help from throughout the UK and considering advances in forensic science all in an effort to help detect this highly unusual crime.”
David Stewart, Labour MSP for the Highlands and islands, welcomed the figures last night.
“This was an absolutely dreadful murder and had an appalling impact on Mr Wilson’s family and the wider community in Nairn,” he said.
“I’m pleased that the police are continuing to make a substantial investment in the investigation. We all want to see this killer caught and brought to justice.”
In June, Nairn residents reported that detectives had been conducting fresh door-to-door inquiries as part of the investigation into Mr Wilson’s death.
Katherine Paterson, of Douglas Street, said at the time that officers had been in the area for three days.
“They were just trying to get it solved. They just asked if we had heard or seen anything on that night, anything suspicious. But no one heard or saw anything,” she said.
Mr Wilson and his wife Veronica were putting the children to bed when the gunman struck.
The murderer was described as between 35-40, stocky and clean shaven and wearing a baseball cap.