Gerald Stephens, 42, and Christine Rees, 37, were beaten and stabbed before being shot in the head at the firm's offices at Risca, Gwent, at 1.30am yesterday.
Gwent CID confirmed that inquiries were centred on the personal background of the victims. Mr Stephens, a father of two, was co-owner of the firm; Mrs Rees, a mother of four, was a regular driver but also helped with office work.
Robbery was ruled out as a motive after wage packets were found.
'The couple were shot from very close range. It was likely they knew their killer,' police said.
A man was last night helping police with their inquiries.Reuse content