Friends Rachel Cullen and Sophie Luke had gone out to The Angel JD Wetherspoons in Basingstoke, where Rachel went up to the bar to order a round of vodka, lime and lemonade.
After standing at the bar 'for a minute', Rachel, 24, brought the drinks back to their table but, just as Sophie, 21, was about to take a sip of hers, Rachel realised that the drink was fizzing. Watch their video here:
On closer inspection Rachel spotted a small white pill sitting at the bottom of Sophie's glass and reported it to staff.
"It's frightening to think what could have happened," said Rachel.
"As soon as we saw it'd been spiked we said, 'oh my god, what's just happened?' We were just in complete shock. It was scary, I don't like thinking about it, it's just awful that it happened.
"She didn't touch her drink for about ten minutes, which is why it was still, and why I was able to see that it was fizzing as much as it was. Thankfully no one had drunk from it - we caught it early enough."
After the girls reported it to the bar manager, he 'did everything he could to help'.
Rachel recalled: "He gave us two new drinks with those anti-spiking lids on and we checked the CCTV, but both the smoking area and the bar were in blind spots.
The girls then made a point to alert everyone else at the bar to watch their drinks, handing out more drink lids at each table.
After sharing the footage on social media, Rachel is now speaking out about her friend's near-miss to highlight what happened and urge revellers to 'watch their drinks'.
"It's one of those things where I wasn't immediately paying attention to what was happening with the drinks because you don't expect it to happen", she said.
"I just want people to be aware and watch themselves and watch their drinks, to stop it happening and protect people in the future.
"If I were to speak to the person who did this, I'd say 'take a step back and look at yourself and how your actions have consequences. I'd also say, 'what if it happened to your daughter?' I just personally can't comprehend why they'd do that, I can't understand it."
Commenting on the incident, Wetherspoons spokesman Eddie Gershon said: "We were made aware by a customer that there had been a foreign object in her drink which appeared to be some form of tablet. The drink was immediately replaced and covers for her and her friend’s drinks were provided.
"We reviewed CCTV both of the drink at the bar and whilst on the customer’s table but could not see if it had been interfered with in any way. We are happy to cooperate with the police in any investigation.
"We have reiterated to our pub team the need for vigilance and posters will be displayed on the premises advising customers to be aware of any suspicious behaviour around their drinks. Drinks covers are available for customers on request."
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