7 countries took suspicious equipment to Sochi
Fireworks explode around the Fisht Olympic Stadium at the end of the Closing Ceremony of the Sochi Winter Olympics on February 23, 2014 at the Olympic Park in Sochi - by Jonathan Nackstrand
Russian security services also found syringes and needles in five athletes' apartments, said the World Anti-Doping Agency (WADA) report.
At least eight athletes faced disciplinary hearings for banned drugs during the Winter Games in February. Four athletes were excluded from the event before it ended.
The WADA observer mission to the Games said that Russian customs scanned 16,000 bags in the buildup to the Olympics and during the Games.
"Seven named nations were identified as importing 'large amounts of intravenous systems' as well as other medical equipment," said their report.
"On five occasions the Federal Security Services 'detected the use of needles and syringes in the living quarters'" of unnamed delegations, it added.
The International Olympic Committee warned all team doctors before the Games that intravenous equipment, blood analysing machines and oxygen boosters were not permitted in the Olympic village, the observers' report said.
The observers said they were only made aware of the information in a draft report given to them by Russian officials towards the end of the Olympics.
The observers said they needed more "professional expertise" to help interpret the scanner images and to take follow up action. But they praised heightened measures taken for the Olympics.
Some 45% of the 2,902 athletes who competed in Sochi underwent a drugs test, the report said.
"The IOC had planned the most ambitious anti-doping program for the Sochi Games and should be highly commended for the concept of significantly increasing the amount of testing conducted before the athletes competed," said the report.
The observers added that their mission "was of the view that the Sochi Games were a milestone in the evolution of the Olympic Games anti-doping program and that the initiatives observed will, if further progressed, have a positive and long lasting impact for clean athletes in the future."