The Trade Ministry on Friday said it was conducting random sampling of meatball soup sold by vendors in Greater Jakarta, threatening five-year prison terms to those proven to be mixing pork into ostensibly pure-beef meatballs.

The ministry made the move after police raided a factory producing meatballs – better known here as bakso – in Cipete, South Jakarta, on Wednesday, alleging that workers there were adding pork to bakso that its makers claimed was purely beef.

On Thursday, West Jakarta administration officials found three beef bakso mixtures containing pork out of 34 samples taken from a number of markets in West Jakarta.

Deputy Trade Minister Bayu Krisnamurthi said producers of such bakso were in violation of Indonesia's consumer protection law, unless they informed customers that the bakso contained pork.

"We'll do lab tests. If it's true they have deceived the customers, then this is a crime. The punishment will be five years in jail or Rp 2 billion ($207,000) in fines," Bayu told journalists in Jakarta on Friday.

Bayu said his office took random samples from bakso vendors and producers in Senen, Central Jakarta; Rawamangun and Cempaka Putih in East Jakarta; Darmaga in Bogor; and other locations.

He added that the illegal practice was prompted by soaring beef prices, which have reached about Rp 100,000 per kilogram. Pork prices, meanwhile, range between Rp 30,000 and Rp 40,000 per kilogram.

"The traders indeed do this on profit considerations," Bayu said, as reported by Indonesian news portal detik.com.