Jehovah's Witnesses. review: suspected adultery/ infidelity

I have a strong suspicion that there is gross infidelity and possible adultery between a JW Elder and a female congregant.
My suspicion arises from observing the two accused on many occasions when they are at the same venue, and also from furtive phone calls and messaging each other numerous times daily. The communication starts with messaging in the early hours of the morning, continuing at hourly intervals until around midnight. The Elder has an invalid wife and the woman Witness had an unbelieving husband who has now also been baptised recently, mainly for reasons to become a more loving, kind and compassionate husband. The wife has separated from her husband for over ten years, the reason, as she complained to the Elders, were because he did not support her adequately financially and also because she wanted freedom from his 'oppressive' behaviour. This complaint was that he was jealous of her men friends' admiration of her. Also she felt he was too possessive and overbearing. So she found the 'catch' she was looking for all her life when the over friendly Elder's attention turned into her 'much desired attention'. All this has been going on for around 6 to 8 years from the time the Elder joined her congregation. My suspicion arose when I started noticing about 3 or 4 years ago, that when a voice call or SMS, supposedly came on her phone from him, she will not reply, in the presence of her husband, children or visitors. If the call or message was from someone else, she will anounce who it is and talk 'over loudly' to show that it was an innocent call from a friend or a relative. The most telling evidence seems to be, when assumably, she gets a message or call from the Elder, she rushes into the shower after answering the call, putting on unusually higher amounts of make up and perfumes and drives off in a hurry, presumably for the arranged rendevous or possible or probably sexual encounter. She would return after about 2 hours or often after 6 to 10 hours. My problem is that I do not know who to lodge this complaint with and who would be interested in investigating this allegation and find the truth. The hapless husband is not financially capable of investigating this case. If anyone can help, please reply to Adam. Email addresss: [protected]@outlook.com