A private investigator has revealed some of the key signs that your partner might be cheating on you. 

According to an online BBC survey of 46,000 couples, one in five married men admitted that they had cheated, while one in 10 women said the same. 

On Newstalk Breakfast, PEL Consultancy Services founder Paul Lewis said there are usually warning signs that trigger a gut feeling. 

“Normally the sort of suspicions would be the mobile phone going upside down, being left hidden consistently, not coming home at a reasonable time in the evening, changes in behavioral patterns,” he explained. 

“I mean, there's all various different signs to relationship affairs and adultery that we've worked on over so many years now.” 

Mr Lewis continued that the number of people who are correct in their suspicions is “probably in the range of about 70 to 75%”. 

“When people have normally got a gut instinct, they're normally right,” he said. 

“Not everyone is right; there's been hundreds of investigations we've done where it just hasn't been the case. 

“But primarily a large proportion of them are pretty spot on really, it's obviously just gathering that then points of intelligence to sort of put the client in a position of strength and understanding. 

“A lot of the affairs take place in the in the workplace; so, it just depends on what the arrangements and living circumstances are of the individuals that we're currently investigating really.”

While people can cheat on their partner at any time of the year, Mr Lewis said there is traditionally a spike in enquiries at certain times of year.

“Normally it starts in the middle of summer really and then up to the Christmas period,” he said. 

“But what we found over the years is that January is quite a busy month, due to sort of people going missing over the Christmas period.

“And a lot of affairs start in the workplace over the course of that period due to the Christmas parties and things like that.”

Main image: Shocked lovers. Picture by: Alamy.com.