A Swiss television programme claimed on Thursday that the incident happened before the penultimate stage of this month's Tour of Switzerland.
Lampre is led by the world champion, Oscar Camenzind, who won a stage and finished fifth overall in the Tour.
The programme said one of its reporters had watched the Lampre team car drive to an isolated container and discard a rubbish bag at the end of Wednesday's stage from Nauders am Reschenpass to Arosa. The reporter retrieved the sack and found it contained drugs and syringes.
A sports doctor, Walter Frey, told the programme that four of the 13 drugs found in the sack were on the International Cycling Union's banned list. He said they were in the category of cortisone anti-inflammatories. Several of the drugs are undetectable in current urine tests, Frey said. Labels on the drugs showed that most of them had been bought in Italy, the programme said.
Approached at the end of the Tour, Camenzind reacted angrily to the story. He told a reporter he had been tested three times during the 10-day race and nothing had been found. He added that he was being accused without proof. Lampre bosses refused to comment.