SCAM
1 - if they were in the UK why are they using a free CHINESE email account?
2 - There is NO such thing as an Afffadavit of Guarantee in the UK
3 - The British High Court is a criminal court that prosecutes murders, rapists and other serious criminals. They have nothing to do with immigration mattes
4 - There is NO Barrister by the name of Lurd Richard listed with the UK Bar Council so he is NOT a Barrister -- you can check for yourself on the UK Bar Council website http://www.barcouncil.org.uk/about/find-a-barrister/public-access-directory/
5 - If you were not flown to the UK to interview IN PERSON before you received the job offer, it's ALWAYS going to be a SCAM. If you are not an EU citizen a company cannot even apply for a Certificate of Sponsorship to sponsor a foreign worker without proof they have conducted a face to face interview. Phone, email, IM, Skype etc interviews are NOT valid for visa purposes
If you really think that there are people who are going to hire foreign employees over the internet you should not be looking for jobs online because you will be scammed