The four people subpoenaed had conducted their own inquiry in connection with Ketek's approval.
The wealthy founders of the nation's largest assisted-living housing chain for seniors, the Klaassens are currently cooperating with a government inquiry in connection with accounting practices and stock options exercised by them and other company insiders.
Det Sgt Jennifer Priestley, of Police Scotland, said: "We're currently following a positive line of inquiry in connection with these incidents.
At present there is only a very narrowly defined provision in the Employment Ordinance which states that, 'an employer shall not dismiss an employee by reason of his giving evidence or information in any proceedings and inquiry in connection with the enforcement of the Employment Ordinance, work accidents or breach of work safety legislation'.
He was accused of actively blocking bids by two foreign banks, and is the subject of two criminal inquiries in connection with those bids.
ABC's Mike Levine: "Mueller's team investigating whether...Trump sought to obstruct a federal inquiry into connections between his presidential campaign and Russian operatives has now directed the Justice Department to turn over a broad array of documents, ABC News has learned.
A spokesman for the force said: "We have got officers in the area assisting with inquiries in connection with the missing child benefit data". Earlier this month, BBC Radio 4's Money Box programme reported that a CD containing the personal details of thousands of Standard Life pension holders had gone missing.
Their inquiries drew connections between suicide and its social and cultural roots among groups that at the time were marginalized in society: gay men, the obese, schizophrenics and the elderly.
Hogan-Howe said last month that the inquiry had no connection to his decision to retire early.
B5 SPANISH CONNECTION INQUIRY -- The authorities are investigating whether Mohamed Atta, thought to have led the Sept. 11 attacks, met with others involved in the attacks on trips to Spain in January and July.
She has also asked Wanless and his co-author, Richard Whittam QC, to establish whether any of the material mentioned in the internal inquiry or in connection with the 114 missing files was passed to the security services, and if so, what action they took.
