Aliens exist and they live in our midst disguised as humans - at least, that's what 20 percent of people polled in a global survey believe.

The Reuters Ipsos poll of 23,000 adults in 22 countries showed that more than 40 percent of people from India and China believe that aliens walk among us disguised as humans, while those least likely to believe in this are from Belgium, Sweden and the Netherlands (8 percent each).

However, the majority of people polled, or 80 percent, don't believe aliens in our midst.

"It would appear that that there's a modest correlation between the most populated countries and those more likely to indicate there may be aliens disguised amongst them compared with those countries with the smaller populations," said John Wright, Senior Vice President of market research firm Ipsos.

"Maybe the it's a simple case that in a less populated country you are more likely to know your next door neighbour better," he said.

More men than women - 22 percent vs 17 percent - believe that alien beings are on earth.