Days earlier he asked for the boat to be made seaworthy. But the work was not complete when he arrived.
Detectives were also investigating recent financial transactions and cash withdrawals from accounts held by Griffin and Miss Legg.
Miss Legg checked into the five-star hotel, off the Champs Elysees, alone on Monday and was joined by Griffin a short time later.
A cleaner found the room splattered with blood and furniture smashed. Police said there was clear evidence of a struggle.
The couple are understood to have been in a relationship for three years.
Mr Griffin built up a string of businesses including tanning salons and gadget shops across the north-west of England.
But reports said the business floundered and he was declared bankrupt in 2006.
The couple used to share a home in Knutsford, Cheshire, but more recently they lived in Oxshott, Surrey.
