Ahead of a Swiss referendum on the country's plan to buy 22 fighter jets from Sweden, a report has raised concerns that a US-made communication system could be used for spying.
According to a report in Swiss weekly Le Matin Dimanche on Sunday, Swedish defence firm Saab last year brought in United States company Rockwell Collins to replace Roschi Rohde & Schwartz of Switzerland, which had originally been contracted to build the communications system.
While the Swiss would still be make their own encryption keys, the box and the software inside would be US-made, according to the report.
Following the trove of disclosures by former US intelligence contractor Edward Snowden of Washington's widespread spying efforts, the American firm's reported role raised eyebrows.
"With the Americans, it would be surprising if there were no back doors," Richard Morva, head of the Swiss Crows association that deals with electronic warfare, told the paper.
When contacted by Le Matin Dimanche, both Saab and the Swiss ministry stressed that the deal had "never excluded the use of non-European components".
The most recent polls show that a majority of Swiss voters oppose the plan to buy the Swedish Gripen fighters, which would cost 3.1 billion Swiss francs (HK$27.1 billion).
Voters are set to cast their ballots on the issue on May 18.