Inflows into gold exchange-traded products have hit their highest levels since February 2013, according to ETF Securities.

Inflows into gold exchange-traded products have hit their highest levels since February 2013, according to ETF Securities, saying that an upcoming Swiss referendum on a proposal to make the central bank stock up on gold was a factor.

Physical gold ETPs totalled $131.8 million last week on a combination of bargain hunting and potential for a "yes" result at the Swiss gold referendum. At the end of this week the Swiss will vote on whether to require their central bank to hold 20 per cent of its assets in gold. Opinion polls only show 38 per cent of the population is in favour of the proposal, however.

"Gold inflows rose to their highest since February 2013 last week following a 2.4 per cent gain in price. With gold having fallen close to its marginal cost of production, investors increasingly believe that mine production will be cut in 2015, helping to tighten supply," said associate director Nitesh Shah.

Elsewhere in the ETP market oil ETPs saw the eighth consecutive week of inflows with a total of $10.8 million. Silver ETPs saw the third consecutive week of inflows, copper ETFs had strong inflows, while on the other side of the coin natural gas and soybeans were among the commodities seeing outflows during the month.